Space Shift Keying (SSK-) MIMO over Correlated Rician Fading Channels: Performance Analysis And a New Method for Transmit-Diversity

In this paper, we study the performance of Space Shift Keying (SSK) modulation for a generic Multiple-Input-Multiple-Output (MIMO) wireless system over correlated Rician fading channels. In particular, our contribution is twofold. i) First, we propose a very general framework for computing the Average Bit Error Probability (ABEP) of SSK-MIMO systems over a generic Rician fading channel with arbitrary correlation and channel parameters. The framework relies upon the Moschopoulos method. We show that it is exact for MIMO systems with two transmit-antenna and arbitrary receive-antenna, while an asymptotically-tight upper-bound is proposed to handle the system setup with an arbitrary number of transmit-antenna. ii) Second, moving from the consideration that conventional SSK-MIMO schemes can offer only receive-diversity gains, we propose a novel SSK-MIMO scheme that can exploit the transmit-antenna to increase the diversity order. The new method has its basic foundation on the transmission of signals with good time-correlation properties, and is called Time-Orthogonal-Signal-Design (TOSD-) assisted SSK modulation (TOSD-SSK). It is shown that the proposed method can increase twofold the diversity order for arbitrary transmit-and receive-antenna. In particular, for MIMO systems with two transmit-antenna and N-r receive-antenna full-diversity equal to 2N(r) can be achieved. Analytical frameworks and theoretical findings are substantiated via Monte Carlo simulations for various system setups.